Not making this up: Scientific journal wonders whether taking placebo should be a doping offense

So is the use of real morphine before the placebo doping?

What is someone needs morphine for another condition but uses it to aid sports performance as well and then goes the placebo route for a competition?

IS that really fair to other competitors who lack that same advantage?

There's no need to wonder. Improving performance in this way is a doping offense because the out-of-competition morphine is a doping offense. Morphine is on the WADA list of prohibited substances:

S7. NARCOTICS

The following are prohibited:

Buprenorphine, dextromoramide, diamorphine (heroin), fentanyl and its derivatives, hydromorphone, methadone, morphine, oxycodone, oxymorphone, pentazocine, pethidine.

The placebo itself is not doping, but since the placebo only works under this theory because it is preceded by illegal doping, there's no way to improve performance in this way and comply with WADA.

JPL wrote:What is someone needs morphine for another condition but uses it to aid sports performance as well and then goes the placebo route for a competition?

IS that really fair to other competitors who lack that same advantage?

There I don't think the answer is quite as simple. I assume it would be no trouble to get a TUE for morphine use if you were undergoing surgery and maybe shortly afterwards.

Maybe not with morphine, but I can see the issue coming up with less powerful narcotics and, for example, throwers with back pain, runners with PF, where a doctor might normally prescribe narcotic painkillers but using them gives one an unfair advantage in competition. I assume you couldn't get a TUE for that kind of chronic pain, but I don't know.